The present invention relates to a device for feeding a washing liquid to two spraying nozzles spaced from each other so as to wet either two spaced areas of a windshield or the front windshield and a rear pane of the automobile.
A liquid delivery device of the type under discussion has been disclosed, for example in DE-OS No. 8336073. The device has two pressure chambers separated from each other by a limiter which is formed by a diaphragm which alternatively closes each of two pressure chambers, depending on the direction of rotation of the pump rotor, so that the washing liquid flows via the one or another outlet to the respective spraying nozzle.
Such devices are often utilized for moistening the front and the rear panes of motor vehicles and at least one of the spraying nozzles can be disposed in the region body of the vehicle, in which lower pressure is built up during the travel of the vehicle so that the washing liquid can be sucked from the device. This can, however cause an idle suction of the liquid from the feeding pump which is normally a non-sealed flow pump to the liquid supply tank which belongs to the system.
When such conventional device is used, for example for moistening the front windshield and the headlight pane the entire system arranged deeper or lower than the supply tank to empty the spraying nozzles corresponding to the headlights to prevent said undesired suction effect.
In order to avoid the situation that no liquid would be available in critical conditions the feeding lines between the pump and spraying nozzles must be provided with check valves.